Dog seizures: causes, symptoms, and what you should do

A dog seizure can take on many forms, depending on the type of seizure and the breed of your dog. Whole-body seizures or grand mal seizures can cause a dog to convulse all over. Localized or partial  seizures may only affect one part of the body or present as a sudden onset of rhythmic movements (tremors) or actions. The most common signs of seizures in dogs are:

• Salivating or foaming at the mouth
• Stiffening of the legs and neck
• Jaw clenching
• Muscle twitching
• Jerky body movements
• Paddling of limbs
•  Vocalization
•  Dilation of the pupils
• Collapsing and/or loss of consciousness
• Involuntary defecating or urinating

Many dogs will become anxious or clingy before a seizure and remain wobbly and disoriented after the seizure has ended. Some dogs may be permanently blind after a seizure if the seizure is caused by a brain lesion.

While epilepsy is the most common cause of seizures in dogs, there are several other triggers to look out for. Regardless of the underlying cause, all seizures occur due to faulty electrical activity in the dog’s brain, which leads to a loss of control over the body.

Epilepsy – Dogs can be considered epileptic if they experience two or more seizures. Epilepsy can be classified into two main groups: idiopathic seizures, which have no apparent underlying cause, and symptomatic seizures, which do. While veterinarians don’t know the exact cause of idiopathic epilepsy, there’s evidence to suggest it’s genetic.

Heatstroke and heat exhaustion — An overheated dog can suffer critical damage to its brain, heart, liver, and nervous system. Heat-related brain swells can trigger dog seizures in a matter of minutes.

Nutritional imbalances — Mineral, vitamin, and amino acid deficiencies have all been linked to canine seizures.

Poisoning — Dog seizures have been linked to toxins found in household alcohols, heavy metals, human medications, carbon monoxide, foods like caffeine and chocolate, certain plant species, and compounds from other animals like bufo toads and killer bees. These aren’t the most common triggers for seizures, but it’s important to keep in mind that the ASPCA fielded more than 400,000 calls in 2021 to its Animal Poison Control Center.

​​👉 Not sure if a certain product is toxic to your dog? Check out this comprehensive list from the FDA.

Head trauma — Several studies have found links between post-traumatic epilepsy (PTE) in dogs with severe head injuries.

Infectious diseases — Viruses that attack the central nervous system like canine distemper and rabies have been shown to trigger violent, sometimes lethal, seizures, in addition to tremors, twitching, imbalance, and limb weakness.

Diabetes — Dogs with diabetes can have seizures if they receive too much insulin or receive it before eating. The insulin causes their glucose level to become too low which is known as hypoglycemia. This condition is a medical emergency and will lead to seizures and a coma if not treated in time.

Tumors — Seizures are common signs of brain tumors in dogs. If your dog just started getting seizures and they’re five years of age or older, a brain tumor must be considered as a possibility. Only advanced imaging (CT scan or MRI) of the brain can determine if a brain tumor is present.

Many types of visits to veterinarians are covered by pet insurance — find out what is (and isn’t) covered by reading our pet insurance coverage guide.

Dog breeds susceptible to seizures

Epilepsy is more common in dogs than in cats. While all dogs are susceptible to seizures, these breeds tend to be more prone to them than others:

• Bull terriers can suffer from an inherited form of epilepsy that causes behaviors like tail chasing, irrational fear, and unprovoked aggression.
• Dogs that carry the MDR1 genetic mutation can develop seizures if given certain medications like ivermectin and loperamide. The most common breeds to have the MDR1 gene are border collies, Saint Bernards, Bernese mountain dogs, Australian and German shepherds, golden and Fox red Labrador retrievers, longhaired whippets, Irish setters, and Old English and Shetland sheepdogs. A genetic test can be done to determine if your dog has the MDR1 genetic mutation.
• Breeds with short, flat noses like boxers, pugs, Boston terriers, and American bulldogs can experience seizures secondary to heatstroke. It is important for these breeds to only be outside briefly on days that are hot and humid.
• Other breeds prone to idiopathic epilepsy include beagles, dachshunds, cocker and springer spaniels, Welsh corgis, wire fox terriers, Keeshonds, Siberian huskies, and poodles.

Idiopathic seizures occur when a dog has no identifiable underlying condition. Vets today believe that most idiopathic seizures are caused by genetics.

Structural epilepsy occurs where there’s an identifiable underlying brain lesion (hydrocephalus, tumor, stroke, meningitis, degenerative changes), infectious disease, or trauma.

Reactive seizures are caused by a metabolic disease or toxicity.

Seizures can be scary when they’re happening, but it’s important to remember that they’re not painful for dogs. While it may seem like there’s nothing you can do when your dog is having a seizure, there are a few ways to keep them comfortable and help them get through it safely.

Avoid restraining your dog during an episode and keep your hands away from their mouth. Most seizures are self-limiting and will stop after about 30 seconds to a minute. Make sure your dog can’t fall or hurt themselves on anything in the area. If the seizure goes on for five minutes or more, bring your dog to the nearest emergency hospital where vets may need to administer anti-seizure medication.

If possible, take a video of the seizure-like episode and show it to your vet. Keep a journal to log any seizure your dog has. Include the date, what your dog was doing before the seizure, any changes that occurred that day, where the seizure took place, and how long the seizure lasted.

When to see a vet

You don’t need to call your veterinarian every time your dog has a seizure, but when your dog has a seizure for the first time or starts having seizures more often than usual, you’ll want to contact one as soon as possible. You should also contact a vet immediately if your dog’s seizure lasts longer than five minutes, if your dog has more than two seizures in 24 hours, or if you think your dog has ingested something poisonous.

Treatment will differ depending on the cause of your dog’s seizures. Your vet will focus on seizure control in the case of idiopathic epilepsy or addressing the underlying issue if your dog has another condition. Treatment should start as soon as a definitive diagnosis is made. Your vet will work with you to determine the best treatment options, which may include medications or keeping a seizure diary. There are even a few smartphone apps made specially to help pet owners keep track of their dog’s seizures.

CBD is also being studied as a natural alternative to traditional medical treatments for dog seizures. While ongoing studies have been promising, there’s still a lot we don’t know. Make sure to follow the instructions on CBD product labels to find the right dosage for your dog and always check with a veterinarian before starting a new supplement or treatment.